This application, in response to a request from the Neurodegeneration and Clinical Trials Groups of the NINDS, provides data in support of our ability to become a clinical center to collaborate in the performance of a large, double-blind randomized trial of two or more potential neuroprotective agents in patients early in the course of Parkinson's disease. Our group has been conducting clinical trials in Parkinson's disease patients since 1983. We have a large patient population and a wide referral network. Administrative and coordinating systems necessary for the successful completion of such a trial are already in place and working. We have a record of adhering to similar common protocols and cooperating with other centers and will do so for this trial.